Characters/Pairings: Dean/Sam, Dean/Buffy, Dean/Sam/Buffy

Spoilers: general season 4

Summary: Giles and Sam confer with an expert from the Watcher's Council. Willow and Xander make a cameo, and Dean takes his ever-building needs to the street. Supernatural/BtVS crossover.

Legal disclaimer: I do not own Supernatural, I do not own Sam or Dean. If I did, I would be far too busy to ever write anything ever. I also do not own Buffy or Giles the Scoobies.

--

As soon as it became a reasonable hour on both sides of the ocean, Giles was on the phone, contacting one of the Council members in England. William Atherton was an expert on succubus myth and legend, and although rather new to the Council, already a very highly regarded scholar. He was also something like a protégé to Giles. Sam was the only other person awake in the whole house. Truth be told, he hadn't been able to sleep very well last night, plagued with disturbing dreams he could only half remember. He'd awoken before the sun came up with a sequoia stuffed down his pants, so that gave him a hint of the content of his dreams, if not the specifics. He'd put the hide-a-bed away and now sprawled across the sofa in a tangled array of arms and legs and pillows and blankets.

Giles sat on Buffy's black leather recliner, the cordless receiver rested between his ear and shoulder while balancing a pad of paper in his lap. "William? Yes, I'm doing very well, thank you. No, actually, I'm calling to get your opinion on something. Hold on, I'd like to put you on speakerphone."

Giles fiddled with the phone for several seconds, until Sam finally took pity on the man and located the button on the base station for him.

"Bloody machines. Just as bad as the idiot boxes. Yes, well," Giles cleared his throat and composed himself once again. "I've just had some friends of a friend come seeking my assistance. I believe one of them has been a victim of a succubus. The boy complained of being bitten two nights ago, and has been er, aroused ever since. Perhaps the feeding caused some unforeseen consequences."

Sam was surprised at how young Atherton sounded when he replied. "Mr. Giles, I believe what you are describing is a result of the succubus procreation ritual, not a simple feeding. Succubi don't bite those they feed from. The Latin succubaire or sub cubare literally translates to 'one who lies beneath,' which is a clue to how they obtain sustenance; they drain the energy created by their partners during sex. They are only venomous in certain circumstances, such as when they go into heat."

Sam didn't really know exactly what that meant in the context of a demonic seductress, but he had a pretty good idea, and it all added up to a sinking feeling in his stomach and trouble for Dean. He glanced over at Giles, who was listening attentively and taking notes on his small pad, having taken a time out from looking down every few seconds to polish his glasses on his shirt.

"There have been very few documented cases of succubus poisoning," William continued. "Some academics in the field actually doubt its existence, but from what I've been able to piece together from first and secondhand accounts, it is a very real phenomenon. Usually the infection is followed by rampant coupling and the eventual disappearance of the victim. In one case, there were eyewitness accounts of a man reappearing twenty years after he'd vanished without a trace, seeming to have not aged a day. Following the man's return, there was a rash of hospitalizations of the male populous due to exhaustion. It is quite possible that succubae do not age as humans do. Their metabolic needs are quite different."

Sam thanked God that Dean was still sleeping; his brother would probably have an aneurism if he'd overheard the Brit's words. "Mr. Atherton," Sam began, carefully measuring his voice for politeness and respect, regardless of how urgent he actually felt, "my name's Sam Winchester. It's my brother who was attacked. Are you suggesting that it's possible that these victims somehow become succubae themselves?"

"I'm sure of it," she scholar answered. "The evidence is quite conclusive, though of course the Council has never had an actual succubus to study. I am quite excited to be able to document this case." The man was too damn eager, in Sam's opinion. "I'm sorry about your brother," Atherton added belatedly.

"Well has anyone ever stopped it? Found a cure, anything?" Dean was turning into a succubus? Giles's Codex had suggested it, but now he'd gotten confirmation from a scholar devoted to the study of these things. God he'd hoped he'd been wrong. Sam guessed that was why he hadn't been able to take his eyes off his brother. He knew it was sick and wrong, and he was seriously weirded out…but physically his body responded to Dean. He wasn't gay; it was just the venom talking. But his body's reaction while Dean was around made it damn hard to concentrate.

There was a pause on the other end, as if the Council member was pondering, trying to remember if anyone had escaped their fate. "I've never heard of antivenom," Atherton finally replied, "though the infection itself feeds off of sex and arousal, so the more potent the feelings, the swifter the transformation. I'll keep my eyes open for any new information on this, but it would be helpful if I could have a blood sample."

Giles's eyes brightened in excitement. "Good idea William!" he exclaimed. An occurrence like this was a rare chance to increase the knowledge base of the Council.

"Man, Dean's not gonna like that. He hates hospitals."

"No, I'm afraid we can't risk taking him to a hospital. Not in his current condition." Giles set his notebook down on the coffee table and sighed. "Thank you for your assistance, William. You'll let us know as soon as you find anything?"

"Yes, yes of course. Goodbye, Rupert."

"Goodbye."

Sam imagined his brother in a hospital, around that swarming throng of humanity, his eyes dilated and bright. Sam could read Dean better than anyone, and those jewel-like emerald eyes held fear and lust in damn near equal measure. He could almost feel the tight grip he'd have to keep on Dean's shirt, restraining him and anchoring him. Forcing his brother to remain in the here and the now and not wherever the venom was taking him. Dean would try to slip him, of course, but Sam would be ready for the attempt, and pin his brother against the wall. They'd be so close like this, Sam's larger body able to touch every part of Dean, able to dominate his older brother.

Oh, fucking hell. He'd tried to pass the previous night off as a fluke; the weird sex dream was obviously from going so long without. It certainly hadn't been about Dean…had it? He loved Dean, sure, of course, but he didn't want to make love to Dean…well, he shouldn't. He knew he shouldn't, intellectually. Sam's brain and his dick didn't seem to be on speaking terms at the moment.

Sam forced himself to think and it really shouldn't have been that hard to make his brain function, to figure out what was happening to him. Dean was awake. Awake and somehow projecting his desires onto those nearby. All those thoughts were focused on one pure need, and it was making Sam's cock more than half-hard.

Sam excused himself awkwardly, maneuvering carefully and trying to hide his erection. Damn it, he hadn't been this out of control of his body since puberty. "I'm gonna go see if he's up yet," he informed Giles, who merely nodded his acknowledgement, not looking up from the glasses he seemed to have gotten smudged yet again.

Sam padded down the hall with no small amount of trepidation. "Dean, you awake?" Sam called from a safe distance, voice laced with concern. If there was a slight tremor there too, well, it was a closer cousin to yearning then fear. Dean was broadcasting pretty damn loud. Sam heard an answering muted groan from the other side of the barrier. Sound carried surprisingly well though the bookcase and bedroom door. "Hey man, so Giles talked to this guy in England, and he's gonna help find a cure for this," Sam tried to reassure Dean from the other side of the door. It was as close as Sam was really comfortable getting in his confused emotional state. Their relationship since Dean had returned from Hell was strained enough as it was. Acting on this thing between them could fuck it up beyond repair.

But God damn it, ninety percent of his thoughts were consumed with Dean. While that was nothing new, the subject matter had changed drastically. Sam's thoughts centered on how Dean's soft lips would feel against his cock, how soft his hair would be as Sam buried his fingers in it, tugging on it firmly as he guided his brother's mouth. Dean's skin welted so easily—had since they were kids—it wouldn't even take much pressure to raise swollen red lines with his fingernails. Mark him up, let everyone know that Dean was his. Sam's breath came in short gasping pants and his dick strained toward the door, toward Dean.

"Yeah," his brother replied bitterly. "Sammy…you need to…god, fuck you smell good. You need to get away from the door. Need too…." Dean's voice trailed off into what Sam hoped weren't choked sobs. If they were, he'd allow Dean the dignity of pretending he hadn't heard them even while his heart broke for his brother.

"All right," Sam said, retreating. Walking away was one of the hardest things he'd had to do in a long time. "I'll just get some breakfast, okay? Don't…just don't touch yourself, you know?" When he got no response, Sam treaded to the kitchen, praying his erection would subside before anyone else could see him in this state. But if he couldn't indulge one hunger, he'd at least take care of the other. We'll find the answer, Sam promised himself. He'd let Dean down once before, allowed Lilith to drag him to Hell bloody and screaming. It wasn't going to happen again, even if he had to take Ruby's offering. He'd be strong, he'd save Dean and destroy anything that tried to tear them apart.

Buffy had journeyed downstairs sometime in the intervening time, and the smells coming from the kitchen hinted at food that might just be fit for human consumption. Giles was already at the table, spreading jam on a muffin and seeping a tea bag in a mug of hot water that read "World's Best Librarian." Sam figured it was probably a custom job.

"Hey, I'll reinstate the phone circle," suggested Buffy when she saw Sam enter. "Wills and Xander are off today; it's a great excuse to get the original Scooby Gang back together again." In fact she seemed somewhat excited, like a puppy with a new toy and an eager partner to play with. "We haven't had a study party for like, ages. Not since I semi-retired from the whole Chosen One gig."

"You want Willow and Xander here in the house? At the same time?" Giles's voice held a note of carefully restrained panic.

"Come on, Giles! It'll be like old times!"

"Yes, that is what I'm afraid of."

--

Willow and Xander joined them around midday, bringing with them welcome sustenance in the form of highly caffeinated soda and bags of salty goodness. Buffy introduced them to Sam, and while he envied Buffy her friends, he liked them immediately. Xander's ready smile and humor and Willow's predisposition to fluctuate from hyper to serene…they reminded him of different times. Back when he had friends, people who didn't know about the life he'd been born into. He hadn't even talked to his friends in years; they were part of an ill-fitting life that didn't belong to him anymore, if it ever had.

Sam was amazed at how well they worked together, how in sync their thought process was. Xander would begin a sentence, and Willow or Buffy would finish it, providing some personal insight that would then spur them on to the next idea. Giles had begged off for the evening. "The three of them together in the same room? Well, I fear that is a situation best left to far younger men than I." He could see the elder man's point; being in the same room at them was mentally draining, especially trying to interpret their strange personal language. He was very much on the outside looking in, and it shocked him how much he resented their closeness. He had Dean, and lately they'd been silently drifting apart from each other.

The four of them looked for anything to do with warding off a succubus, with preventing a person from coming to harm. There were several charms for the latter, but everything they'd found about warding off a succubus was useless in Dean's case. The creature had already got to him. He'd already been infected. They had to find a way to work the venom out of his system somehow, before it could gain in power.

Buffy made Xander take Dean some food, moving the bookcase so he could get in. He also managed to persuade the elder Winchester sibling to donate a vial of blood to science. Wacky monster science, but science nonetheless. Dean didn't talk much, and Sam knew he was sinking into his depression. There was also nothing he could do about it without endangering Dean further.

--

The house was quiet at last. Sam had fallen asleep on the sofa sometime during Buffy's study party, and the Slayer's friends had left a short while after that. Dean had been going stir-crazy trapped in the room with so many people just outside. Only two flimsy barriers had stood in his way, but he was not a monster, damn it. He'd even let the dude with the eye patch (which was really badass, by the way) draw some blood to send to Rupes' buddy. He'd wished for eleventh hour miracles before, and they'd never deigned to grace him. After all, he'd been puréed by Lilith's hellhounds and left to rot in Hell for forty years until Castiel had yanked him out for Heaven's own purposes. Dean pretty much figured he was fucked this time too.

Dean snuck out the window, climbed down the siding and walked, needing to get some space between him and the lingering scents in the house. It wasn't just his sense of smell that had improved either, and yeah, he was really fucking freaked out. He wasn't really going anywhere, just allowing his body to move, one foot in front of the other. His aimless stroll led him past darkened streets, abandoned alleyways, and finally to three-story building alit with neon in warm shades of orange and yellow.

It looked like a local club, with a line of half-dressed people stretched around the building, waiting for their chance to see if they were hot enough, connected enough, rich enough to be accepted inside. Dean smiled; it was not a nice smile. It was all teeth and bite. It was predatory and fierce, but genuine. He was about ready to pounce on the closest thing that moved, and maybe if he could ease some of his urges here, he could protect Sam. Dean's need for sex didn't discriminate, he would fuck anyone—including his brother—given the opportunity, and he would not allow that to happen.

Dean prowled up to the entrance, eyes tracing the illuminated sign idly while he fished into his jacket pocket for a few twenty dollar bills. Solid Gold, indeed. Dean pressed his body against the burly man guarding the door and slipped the crumpled bills into the back pocket of the doorman's pants, giving his ass a playful pat. Dean winked at the guy, still painfully close to him. The doorman groaned, but reluctantly let Dean inside.

The press of people inside the club was a physical sensation, even though no one touched him. It was like he was encased in a protective bubble; everyone was aware of him, but no one would approach. They were given the impression of an untamed beast, beautiful, so fucking beautiful. But dangerous. Maybe even deadly.

"Gimme a beer," he asked the bartender, a woman in her late twenties with vibrant red hair pulled into a messy ponytail and thick black square-framed glasses. Dean grinned at her, and maybe her knees went a bit weak.

Dean felt the soft press of cool flesh against his overheated back before he heard the woman approach, the loud music of the club making it hard for him to differentiate one sound from another. Dean's spine stiffened for a few reasons: shock at being surprised, but mostly trying to stop himself from picking the intruder up and throwing her down on the bar, spreading her legs and burying himself to the hilt inside her. But wasn't that what he'd come for? To do that to some anonymous person so he wouldn't do it to the people he actually gave a damn about? His stomach turned and he tasted bile in his mouth.

Dean grabbed the beer and laid a five down on the bar, taking a long draw from the bottle to rinse the taste of disgust and self-hatred from his mouth. He didn't turn around, just pushed back against her, searching hands seeking the skin of her back and trailing slowly down to the swell of her ass. Deceptively gentle. Dean didn't have it in him to actually feel tender toward any of these faceless bodies, but he'd been faking it for years.

"I've been watching you." Her voice in his ear was whiskey-smooth and seductive as the serpent in the garden.

"Oh yeah?" responded Dean, not turning around. He was beginning to think this was a bad idea. Damn it, he knew what could happen if he gave into this. But he'd sacrifice himself—even surrendering his humanity on the altar of Sam—to protect his brother; he'd done it before and despite the aftermath, he'd do it again.

"Yeah." Her clever fingers tiptoed to the silver button of his Levi's, but didn't move to unfasten them. She just let them rest there, and Dean's cock crept toward her digits with a mind of its own, begging to be stroked, caressed, sucked, anything. He felt like he'd die if he didn't get some stimulation.

Dean grit his teeth against a moan, refusing to voice his desperation. Instead he slammed his empty bottle down on the bar, grabbed her roughly by the arm and dragged her to the fire exit across the dance floor. The alley behind the club reminded him of a different night with a different woman. It was darker tonight though; the only light was coming from the ambient neon glow of the signage. Dean could see perfectly.

He took the woman by the shoulders, his hands huge on her slight frame, and shoved her back against the brick. She couldn't have been much over five feet. Dean lifted her easily and she wrapped her slender thighs around his waist. He was not gentle when he crushed his lips to hers, scraping the inside of his mouth against his teeth. Dean could taste the metallic tang of blood when his tongue begged her for admittance. Her eyes went huge at the rough treatment, pupils blown with only a faint ring of blue betraying the color of her irises. He explored her mouth with sure strokes of his tongue against hers, pausing only briefly to draw breath. She didn't seem to share that requirement, arching toward him when he retreated, desperate for more.

Something was kind of off about this chick, Dean thought, but he wasn't able to process it until he'd gotten her shoved against the rough wall of Solid Gold, his cock sheathed inside her, pounding to the rhythm of his frantic heart. Despite their exertion, she was cool to the touch, had no breath and no answering beat to twine with his in staccato polyrhythms, point and counterpoint to the pace of their coupling. When she moaned, her breath held the scent of old blood. Between one moment and the next, Dean was thrown backwards and a blonde head replaced the sable haired one. The warmth that had enveloped his cock vanished, leaving him bereft and exposed to the cold.

Buffy used all the synonyms for mentally deficient he'd ever heard and some that he was pretty damn sure she'd just invented on the spot. He was covered with fine dust and mourning the loss of the tight wetness around him.

The tiny blonde reached into the pocket of her stylish brown leather jacket and retrieved her cell phone. "Giles? It's me. I found our wayward Winchester." She glared at him reprovingly. "Yeah, we're on the way home now," she replied to the question Dean hadn't been able to catch. Apparently demonic super-hearing had its limits.

Buffy looked down to where Dean had fallen when she'd flung him away from the vamp that had been about to eat his face. "Christ, your brother is right, Winchester. You really will fuck anything that moves – pulse optional," she quipped. He really was very attractive, she thought. She could see his fine bone structure even in the weak light. And he smelled….she couldn't place it, but it was something like the spice of cinnamon and something like the comfort of warm apple pie and something like the ozone left behind when an insect flew too close to the bug zapper. It wasn't much like any of those things, but it made her want to offer herself to Dean. She had more self control than that. She'd played this game with Angel for years, the 'I want you but can't have you merry-go-round.' Pretty as Dean was, she wasn't going to endanger them both by doing something monumentally stupid like giving into demon-induced lust.

She almost changed her mind in the next moment, when Dean got to his feet and slid his muscled body up next her hers. His jeans were unfastened and Dean Junior was saluting her with one winking eye. There was barely a breath between them, and it took everything she had to push him away.

The rough shove knocked Dean back and he almost lost his balance, but he'd been trained better than that. He was shocked at the power of her, and even more turned on. "I'm going to go out on a limb and guess you've never been with a Slayer before. Trust me, Dean, I'm more than you can handle right now," she scoffed.

"Never had any complains before, Sweetheart," he leered, the challenge clear in his tone and body language, but thankfully he backed off. It reminded Buffy of the way she felt after patrolling, desperate with the need to fight or fuck. She though that maybe she was finally starting to understand some of what Dean Winchester was. That was of the bad, since she was just helping him and Sam out as a favor to Giles. She really didn't need any more complications in her life.

Dean was anxious and fidgety walking back to Buffy's house, doing his damnedest not to either touch himself or try to jump the Slayer. "How did you find me, anyway?" he asked, curious.

She hesitated before answering, until he was sure she wasn't going to reply at all. "Slayers have this, well, like a sixth sense I guess. We can sense when vampires and some other demons are nearby. Humans don't trigger it, but you…well, you're starting to."

"So you're like Spider-man or something? Is your Slayer-sense tingling?" he asked with a grin he couldn't help. The whole idea was terrifying, and Dean had learned humor as a defense mechanism before Sam had taken his first steps.

"Dean," she smiled, "shut up."